Individual magnet adjustable pickup



Se t. 30, 1952 H. DE ARMOND 2,612,072

INDIVIDUAL MAGNET ADJUSTABLE PICKUP Filed May 10, 1950 INVENTOR.

Harry 0e Armand A77'DRNEY Patented Sept. 3Q, 1952 UNITED STATES PATENT OFFICE 2,612,072 INDIVIDUAL MAGNET ADJUSTABLE PICKU? Harry De Armond, Toledo, Ohio, assignor-to Rowe Industries, Toledo, Ohio Application May-10, 1950, Serial No. 161,243

' 4 Claims. (01. 84- 115) This invention relates to an adjustable microphonepick up for stringed instruments in which individual magnets may be adjusted undereach string so that the sound waves produced by each string may be individually and variably amplified, thereby producing abalance or other effect between the several strings as desired by the musician.

The main feature of the present invention is to provide a satisfactory means for readily adjusting each individual magnet. To this end, I provide the main coil form with a plurality of openings, one for each individual magnet under each string, whether it be for a fourstringed, six-stringed or eight-stringed instrument. Adjacent, the magnets, I provide in one embodiment of my invention movable adjusting members extending through said unit and located one adjacent each magnet together with means connecting said magnet to said members so that by adjusting the members, the individual magnets may be moved toward and away from the strings. .I also provide spring means for normally retaining said magnets in retracted position which also operates to maintain said magnets in any position of adjustment.

The advantage of my present improvement is to provide an electromagnetic pick up. device in which the individual magnets are separately adjustable. It is a great advantage to have individual magnets because the power of the magnet can be individually localized adjacent each string in contradistinction to the use of, a large magnet.

- Further objects and advantages are within the scope of the invention such as relate to the arrangement, operation and function of. the related elements of the structure, to various details of construction and to combinations. of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure I is a fragmentary view of a musical instrument to which the adjustable pick up unit has been applied; I

FigureII is a full size top view of the pick up unit;

Figure III is a section taken substantially along the line III-III ofFigure II; 1

Figure IV is a section taken substantially along the line IVIV of Figure II;

Figure V is a bottom View of the pick up unit; and

Figure VI is a section taken substantially along the line VIVI of Figure V.

In one embodiment of my invention, as illustrated herein, it will be seen that the electronic pick up unit comprises a coil form In preferably of molded plastic insulating material having the oblong configuration illustrated in Figures II and V, the coil form ID having a surrounding flange H at the base to therebyprovide a cutaway portion into which the winding It may be suitably located, the top surface of the coil form it! having two insulating sheets 15 and I6 secured to the form. The entire unit is placed in ametal frame It, preferably made of brass and chromium plated and provided with a top inwardly extending flange is in contact withtthe edge of the insulating strip 25 and abutting the edge of the top insulating strip it, the top strip being smaller than the lower strip I5 by the width of said flange id as shown. The lower edge of the frame l8 has an outwardly extending flange 23 by means of which the unit may be attached to a musical instrument through a suitable opening made in said instrument, as indicated in Figure I. Y

My invention includes the provision of individually adjustable magnets, one for each string of the instrument and to this end, the coil form it] is provided with a plurality of transverse magnet receiving openings 22 into which the individual cylindrically-shaped permanent magnets 23 are loosely mounted. The. lower end of each magnet is provided with a collar 23 suitablyfixed, as by silver soldering, to the magnet, said collar being provided with a laterally extending wing 25 provided with an opening therein, internally screw threaded as. indicated at 26. Each of the magnets are intended to be located directly under the strings of the instrument ancl centered with respect thereto as indicated in Figure'II. Adjacent each of said openings 22 for the magnets but oiiset with respect to the strings of the instrument as indicated in Figure II, I provide a plurality of transverse openings 28'for loosely receiving the stainless steel, non-magnetic screw threaded shafts 30, each of said shafts having a slotted head 3!, said shafts 30 being screw threaded into the screw threads 28 of the opening on the wing 25 of the collar 24. f A coil spring 33 surrounds each of the magnets 23 and is interposed between the upper surface of the collar 24 and the lower surface of the coil form H] as shown particularly in Figures III and IV to maintain the parts in assembled position and constantly urge the magnets 23 downwardly, the coil spring being of sufficient strength to maintain the magnets in any position of adjustment as determined by the operation of the shaft 38. It will be noted that the head 3| of the screws 33 fit down in the opening therefor in the topmost insulating strip it but contact the top surface of the underlying strip [5 and prevent the screw from passing through the openings 28 in the coil form. As shown in Figures V and VI, suitable leads are provided to connect the pick up device with the magnifying amplifier, the ends of the winding I l being connected thereto as shown in Figure VI.

'Ihecore or coil frame unit Iii with the assembled magnets and adjusting means are suitably secured in the frame [8 by cement or other adhesive or mechanical means.

- The operation of my improved pick up will be appreciated from the foregoing where it will be seen that when it is applied to the instrument, as shown in Figure I, the individual magnets 23 are centered as closely as possible under the strings while the adjusting shafts 30 of non-magnetic material are offset therefrom so that the musician may readily adjust the same by applying a screw driver in the screw driver slot of the head 3| to move any one of the individual magnets toward or away from its corresponding spring, and the magnetic flux is localized as desired. In this way the musician may amplify the tones produced by one string or another to get an over-all balance or other effect as he may-desire. The coil spring 33 is made of sufficient strength to temporarily retain the magnet in any position of adjustment.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

What I claim is:

1. In a magnetic pick up device for stringed musical instruments, said device including an electromagnetic unit having an insulating coil form carrying a winding adapted to be placed adjacent the strings of a musical instrument, said coil form having a plurality of transverse openings therethrough; an elongated individual permanent magnet one movably mounted in each of said openings with one end of said magnet adapted to be positioned adjacent the instrument string; a plurality of transversely arranged screwthreaded shafts carried by said coil form and extending transversely of said unit, one located adjacent each magnet; connecting means between a magnet and an adjacent shaft; and means on each of said screw-threaded shafts for turning the same whereby each of said magnets are individually adjusted toward and away from its corresponding string and maintained in adjusted position.

2. In a magnetic pick up device for stringed musical instruments, said device including an electromagnetic unit having an insulating coil form carrying a winding adapted to be placed adjacent the strings of a musical instrument, said coil form having a plurality of transverse openings therethrough, an elongated individual permanent magnet one movably mounted in each of said openings with one end of said magnet adapted to be positioned adjacent the instrument string; a plurality of transversely arranged adjusting shafts carried by said coil form and. extending transversely of said unit, one located adjacent each magnet; connecting means between a magnet and an adjacent shaft; means on said shaft to prevent the same from passing through said coil form; a spring interposed between said connecting means and the adjacent face of the coil form for maintaining said adjusting shaft and its connected magnet with said holding means on said adjusting shaft against said coil form; and means oneach of said adjusting shafts for moving the same whereby each of said magnets are individually adjusted toward and away from its corresponding string and maintained in adjusted position.

3. In a magnetic pick up device for stringed musical instruments, said device including an electromagnetic unit having an insulating coil form carrying a winding, one face of said form facing the strings of the musical instrument, a frame surrounding said coil form for attaching said unit to a musical instrument, said coil form insulated from said frame and having a plurality of transverse cylindrical openings therethrough, one for each of the strings of said instrument; an elongated individual cylindrical permanent magnet movably mounted in each of said openings in said coil form and adapted to be positioned above or below the face of said coil form opposite the instrument strings; a plurality of transversely arranged screw-threaded shafts extending loosely through said unit and located adjacent each magnet; an enlarged head on said shaft in contact with said coil form; a non-magnetic collar fixed to the end of each of said magnets opposite said face of said coil form facing the strings of the musical instrument, each collar having a laterally extending portion screw-threaded onto the adjacent shaft; a coiled spring surrounding each of said magnets and located between said collar and the adjacent face of said coil form, said spring urging said collar at a slight angle to the plane at right angles to the center of said screwthreaded shaft, thereby to frictionally hold said collar and attached magnet in adjusted position; and means in said enlarged head of each of said screw-threaded shafts for turning the same whereby said magnets may be individually moved toward and away from the corresponding string.

4. In a magnetic pick up device for stringed musical instruments, said device including an electromagnetic unit having an insulating coil form carrying a winding, one face of said form facing the strings of the musical instrument, a frame surrounding said coil form for attaching said unit to a musical instrument, said coil form insulated from said frame and having a plurality of transverse cylindrical openings therethrough, one for each of the strings of said instrument; an elongated individual cylindrical permanent magnet'movably mounted in each of said openingsin said coil form and adapted to be. positioned above or below the face of said. coil form opposite the instrument strings; a plurality of transversely arranged screw-threaded shafts extending loosely through said. unit and located adjacent each magnet; an enlarged head on said shaft to contact. with said coil form; a non-magnetic collar fixed'to the end of each. of said magnets opposite said face of said coil form facing the strings of the musical instrument, each collar having a laterally extending portion screw-threaded onto the'a'dj'acent shaft; a coiled spring located between said collar and the adjacent face of said coil form, for maintaining said enlarged head of said shaft in contact with the coil form and maintaining the position of the magnets relative to the strings of the instrument; and means in said enlarged head of each of said screw-threaded shafts for turning the same whereby said magnets may be individually moved toward and away from the corresponding string.

- HARRY DE ARMOND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES. PATENTS Number Name Date 2,170,294 Dopyera Aug. 22,1939 2,47 9,757 McBride Aug. 23, 1949 2,503,467 Blind Apr. 11, 1950 

